Good news for you hardcore genealogy enthusiasts: scientists have almost completely reconstructed the oldest DNA yet found in a humanlike species.

The DNA in question belongs to the ancient species Homo heidelbergensis and was found in fragments of femur bone from Sima de los Huesos—which translates to the mildly horrifying "Pit of Bones"—in northern Spain. At over 400,000 years old, the DNA is all the more impressive for being the oldest ever found above freezing (and thus preserving) conditions.

Chances are they didn't find your great-times-a-zillion-grandfather, though, since the specimen doesn't appear to be a direct ancestor of modern humans. However, it could be a precursor to both Neanderthals and Denisovans, a group whose remains have only been found far away in Siberia and whose DNA is present today in the genomes of native Pacific Islanders.

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Although they weren't able to sequence the entire genome, the researchers did manage to put together a near-complete vision of the specimen's mitochondrial DNA. That type of molecule, passed only through the mother, yields less than a whole genome but is also substantially more plentiful, with any given cell holding hundreds of copies of the stuff.

This isn't unusual: due to its relative abundance, scientists researching old genomes usually shoot for mitochondrial DNA. But even though the DNA is easy to find, that doesn't mean it's easy to sequence: over time, strands can become corrupted, and in this case it took about two full grams of bone to get enough samples to discern the sequence.